Walsin Inductor Inductance Values: 171 Rungs on 4,769 Rows, and 67 of 168 E24 Cells Are Empty, Counted for UK Designers

Walsin inductor inductance values resolve to 171 distinct rungs. We parsed all 5,410 real rows of Walsin_Inductor_ALL.xlsx, normalised every value to nanohenries and counted: 4,769 rows publish an inductance, 2,940 of them sit on the E12 preferred series, and 67 of the 168 E24 cells the line spans are empty.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds all 203 of Walsin Technology (Walsin) parametric export files and zero inductor datasheets. This post is written entirely from Walsin_Inductor_ALL.xlsx, re-counted for it, with the QA test row Test123999 excluded so the denominator is the real 5,410. Every part number below is real. Because we hold no inductor datasheet, every specification figure here is export-sourced and flagged.

How many distinct inductance values does Walsin’s inductor line actually publish?

171. We parsed all 5,410 real rows of Walsin_Inductor_ALL.xlsx and converted every value to nanohenries first, because the export writes some in nanohenries and some in microhenries. 4,769 rows publish an inductance. The remaining 641 are ferrite beads and carry an ohm symbol in the Unit column instead, so they have no inductance to count. The 171 rungs run from 0.3 nH to 220 µH. We have not seen this counted anywhere.

Decade	Rows in the export	Distinct inductance values	E24 cells filled
0.1 to 0.99 nH	110	7	1 of 24
1 to 9.9 nH	1,575	58	24 of 24
10 to 99 nH	1,414	46	24 of 24
100 to 999 nH	995	27	23 of 24
1 to 9.9 µH	541	20	16 of 24
10 to 99 µH	121	10	10 of 24
100 µH and above	13	3	3 of 24
Total	4,769	171	101 of 168

The ladder is 58 rungs wide at single-digit nanohenries and three rungs wide above 100 µH. That is the shape of the whole decision.

How many of those inductance values sit on the E6 or E12 preferred series?

2,940 of 4,769 rows, which is 61.6 percent. We classified every row by the two-significant-figure mantissa of its normalised inductance and checked it against the E6, E12 and E24 preferred-number sets. E6 alone accounts for 1,664 rows. Adding the six extra E12 mantissas brings it to 2,940. Adding E24 brings it to 4,079. That leaves 690 rows, 14.5 percent, on 70 distinct values that sit on no standard preferred series at all.

Preferred series	Rows	Share of 4,769	Distinct values
E6 mantissas (10, 15, 22, 33, 47, 68)	1,664	34.9%	33
E12, including E6	2,940	61.6%	61
E24, including E12	4,079	85.5%	101
Off the E24 grid entirely	690	14.5%	70

The off-grid values are not noise. 453 of the 690 sit in the 1 to 9.9 nH decade, where RF matching needs 0.1 nH steps and the E-series stops being useful: 1.4, 1.7, 1.9, 2.1, 2.3, 2.5, 2.6, 2.8, 2.9 and 3.1 nH are all real rungs with real part numbers behind them. The other 237 are scattered: 23 nH on 17 rows, 72 nH on 22 rows, 250 nH on 16 rows, and four odd microhenry values — 2.3, 4.0, 4.5 and 6.3 µH — on 10 rows between them.

Which decades are dense, and which decades run out?

The nanohenry decades are complete and the microhenry decades are not. We checked all 24 E24 mantissas in each of the seven decades the line spans. Both the 1 to 9.9 nH and 10 to 99 nH decades are full: 24 of 24. The 100 to 999 nH decade misses exactly one, 510 nH. Then it collapses — 16 of 24 at single-digit microhenries, 10 of 24 at tens of microhenries, and 3 of 24 above 100 µH.

Decade	E24 values present	E24 values we found missing
1 to 9.9 nH	24	none
10 to 99 nH	24	none
100 to 999 nH	23	510 nH
1 to 9.9 µH	16	1.1, 1.6, 2.4, 3.6, 5.1, 6.2, 7.5, 9.1 µH
10 to 99 µH	10	11, 13, 16, 20, 24, 30, 36, 39, 43, 51, 56, 62, 75, 91 µH
100 µH and above	3	everything except 100, 150 and 220 µH

Above 100 µH there are three rungs in the whole line — 100 µH, 150 µH and 220 µH — on 13 rows. The step from 100 µH to 150 µH is a factor of 1.5. No standard preferred series has a 1.5x step anywhere in it. If your design needs 120 µH or 180 µH, this line does not have it and no amount of tolerance stacking will get you there.

Will the inductance my filter calculation wants actually exist, or am I rounding?

Below 1 µH you will almost always find your value. Above 1 µH you will usually be rounding. Take 3.6 µH, a perfectly ordinary output-filter result and a genuine E24 value: there is no 3.6 µH row anywhere in the 5,410. The nearest rungs are 3.3 µH on 55 rows and 3.9 µH on 19 rows, 8.3 percent either side.

Then we did the arithmetic properly. We tested 3.6 µH against the published tolerance window of every row in the export. 52 of 4,769 rows have a window that can legally contain 3.6 µH, and not one of them is tighter than ±10 percent. Every ±5 percent, ±3 percent and ±2 percent row in the catalogue is excluded by arithmetic, not by preference.

Part number	Published inductance	Unit in export	Tolerance	RDC in export	Rated current	Match / mismatch against a calculated 3.6 µH
WLFW2012Z0J3R3PB	3.3	µH	±5%	1.57Ω	330mA	Mismatch — window 3.14 to 3.47 µH never reaches 3.6 µH
WLFW2012Z0K3R3PB	3.3	µH	±10%	1.57Ω	330mA	Match on window (2.97 to 3.63 µH), mismatch on centre: nominal is 8.3% low
WLFW2012Z0J3R9PB	3.9	µH	±5%	1.7Ω	300mA	Mismatch — window 3.71 to 4.10 µH sits entirely above target
WLCW2012Z0G3R3PB	3300	nH	±2%	4.4Ω	90mA	Mismatch — the same 3.3 µH written in nanohenries; DCR 2.8x and rated current 3.6x lower than the WLFW row
MIP25203R3MBE	3.3	µH	±20%	0.1Ω	1200mA	Match on window (2.64 to 3.96 µH), mismatch on tolerance grade and on DCR by a factor of 15
CSME0645D-3R3M	3.3	µH	±20%	28.8Ω as published	3.2A	Match on window, mismatch on footprint — 6060, not 2012 — and the RDC unit does not agree with the current rating
WQCW2520Z0K3R9PB	3900	nH	±10%	3.6Ω	260mA	Match on window (3.51 to 4.29 µH), mismatch on centre: nominal is 8.3% high

We will not tell you any of those is equivalent to a 3.6 µH calculation. We will show you exactly where each one differs, and the pattern is consistent: on this line, hitting an awkward microhenry value means accepting a looser tolerance grade.

Why does the same inductance appear twice in the export under two different units?

Because the export has no single unit convention. We grouped the 4,769 rows by the Inductance value and the Unit column together and got 204 distinct value-and-unit pairs for only 171 distinct inductances. 33 values are published both ways: 47 nH on 72 rows and 0.047 µH on 6 rows, 1,000 nH on 28 rows and 1.0 µH on 52 rows, and so on across 1,590 affected rows.

Inductance	Rows written as nanohenries	Rows written as microhenries	Example part number in each form
1.0 µH	28	52	WLCW2012Z0J1R0PB (nH form) / WLFW2012Z0J1R0PB (µH form)
3.3 µH	28	27	WLCW2012Z0G3R3PB (nH form) / WLFW2012Z0J3R3PB (µH form)

We also checked which series mix the two. Only one does: the WIP_A series. Eleven series publish in nanohenries only, 18 in microhenries only, and 19 publish an impedance in ohms because they are bead series. The unit is a property of the series, not of the part — which is why a sort on the Inductance column alone puts a 3.9 µH part below a 3300 nH part. We have already published the same shape of defect on this line’s RDC column; this is a second instance in a second column of the same file.

Which inductance values are held up by a single part number?

17 of the 171. We counted the rows behind every value. 17 values are served by exactly one part number and 34 by three or fewer. At the other end, the most heavily served rungs are 18 nH and 22 nH at 85 rows each, then 12 nH and 27 nH at 81, then 1,000 nH at 80.

The 17 single-part values are 5.5, 6.9, 7.8, 8.1, 8.9, 10.2, 11.2, 12.1, 12.3, 13.7, 14.7, 15.7, 16.6, 17.0, 19.4, 21.5 and 25.0 nH. Every one sits in the RF matching band, and every one is a single point of failure: one part number, one series, one footprint, one tolerance grade. A value with 85 rows behind it gives you alternatives on size, tolerance and DCR. A value with one row behind it gives you none.

What should a UK designer do before committing a calculated inductance to a schematic?

Check the rung before you check the part. We measured that the ladder is complete to E24 below 1 µH and incomplete above it, so the risk sits entirely in the microhenry decades where buck converters, output filters and common-mode chokes live. Three checks, in the order that costs least.

1. Snap your calculation to the ladder, then recheck the circuit. If your value is below 1 µH, you will find it. If it is between 1 and 10 µH, check it against the eight E24 values we found missing. Above 10 µH, assume you are choosing between 10 of 24 rungs.
2. Decide your tolerance grade after the value, not before it. On the 3.6 µH test, every one of the 52 candidate rows was ±10 percent or looser. A tight tolerance and an awkward value are mutually exclusive on this line.
3. Cross the whole bill of materials in one pass. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool, filter for low profile or high temperature if you need them, and read every stated difference rather than a claimed match. Then check what was physically in Hong Kong on ready stock — a dated snapshot as at 23 September 2026, not a live feed, and inductors are 0.04% of it.

For how the current fields behave on the same rows, see rated current versus saturation current in chip inductors, and for the second half of the value decision, inductor tolerance codes, absolute versus percentage. The whole line is on the Walsin inductor page.

The short version

Walsin inductor inductance values form a 171-rung ladder across 4,769 of 5,410 rows, measured by us from Walsin_Inductor_ALL.xlsx. 61.6 percent of rows sit on E12 and 85.5 percent on E24; 690 rows on 70 values sit off the grid. Both nanohenry decades are complete to E24. One value is missing at hundreds of nanohenries, eight at single-digit microhenries, 14 at tens of microhenries, and only three rungs exist above 100 µH. 3.6 µH does not exist at all, and the 52 rows whose tolerance window can contain it are every one ±10 percent or looser. 33 inductances are published under two units. 17 values rest on one part number each. We hold no inductor datasheet, so every figure here is flagged and sourced. Qualification stays with you.

Send us the inductor lines off your UK bill of materials with the calculated values, not the incumbent part numbers, and we will tell you which rungs exist, which ones you will be rounding to, and what tolerance grade that rounding forces. Then one question back to you: when your filter calculation lands between two rungs, do you move the inductor or move the capacitor?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"How many distinct inductance values does Walsin's chip inductor range have?\n\nWe parsed all 5,410 real rows of Walsin_Inductor_ALL.xlsx, normalised every value to nanohenries, and counted 171 distinct inductances across the 4,769 rows that publish one. The other 641 rows are ferrite beads carrying an ohm value in the Unit column, so they have no inductance to count.\n\nDo Walsin inductors follow the E6 or E12 preferred value series?","content":"Partly. 1,664 of 4,769 rows sit on an E6 mantissa and 2,940 on E12, which is 61.6 percent. E24 reaches 4,079 rows, 85.5 percent. The remaining 690 rows carry 70 values on no standard series at all, mostly 0.1 nH steps in the 1 to 9.9 nH decade where RF matching needs them.","visible":true},{"id":"faq-question-02","title":"Does Walsin make a 3.6 µH chip inductor?","content":"No row in the export publishes 3.6 µH. The nearest rungs are 3.3 µH on 55 rows and 3.9 µH on 19 rows, 8.3 percent either side. We tested 3.6 µH against every row's tolerance window: 52 rows can contain it and every one of them is ±10 percent or looser. We hold no inductor datasheet, so confirm against Walsin's own pages.","visible":true},{"id":"faq-question-03","title":"What is the highest inductance in Walsin's inductor export?","content":"220 µH, on two rows. Above 100 µH the whole line offers three values — 100, 150 and 220 µH — across 13 rows, all in the CSME and CSMEA series. The step from 100 µH to 150 µH is a factor of 1.5, which no standard preferred-value series contains.","visible":true},{"id":"faq-question-04","title":"Why does a sort on Walsin's inductance column come out in the wrong order?","content":"Because the unit is not constant. We grouped the rows by value and unit together and found 204 value-and-unit pairs for 171 actual inductances: 33 values are published both in nanohenries and in microhenries, across 1,590 rows. Only one series, WIP_A, mixes the two internally. Normalise against the Unit column before you sort.”,”visible”:true},{“id”:”faq-question-05″,”title”:”How many Walsin inductance values are served by only one part number?”,”content”:”17 of the 171, and 34 are served by three or fewer. All 17 single-part values sit between 5.5 nH and 25 nH, in the RF matching band. A value with 85 rows behind it, such as 18 nH or 22 nH, lets you trade footprint against tolerance and DCR. A value with one row behind it does not.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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